密质骨各向异性力学性质的分形分析

发布时间：2018-04-08 08:15

本文选题：密质骨　切入点：断裂能　出处：《稀有金属材料与工程》2015年S1期

【摘要】：通过双开口四点弯曲试验测试牛的密质骨沿横向、纵向及径向3个不同方向断裂时的断裂功,结果显示骨沿横向断裂的断裂功最大,纵向次之,径向最小,这表明骨具有明显地各向异性力学性质。对骨断裂后的3个断裂面进行扫描电镜观察,结果显示横向断面粗糙度最大,纵向断面次之,径向断面最小。观察也发现横向断面与骨单元垂直,纵向和径向断面与骨单元平行,可以推断是骨单元与骨间质之间的黏合线使这3个断面上的裂纹发生了不同程度的折拐,这使得这3个断面的粗糙度不同,也使得这3个方向上的断裂功不同。根据骨断裂时裂纹的扩展路径具有统计自相似性,建立骨沿3个方向断裂时的分形模型,用分形理论的能量耗散计算公式,计算了骨沿3个不同方向断裂时的能量耗散,得到的结果与弯曲试验结果有较好的一致。
[Abstract]:The fracture work of dense bone along transverse, longitudinal and radial directions was measured by four point bending test with double openings. The results showed that the fracture work along the transverse fracture was the largest, followed by the longitudinal fracture, and the radial fracture was the smallest.This indicates that the bone has obvious anisotropic mechanical properties.Three fracture surfaces after fracture were observed by SEM. The results showed that the roughness of transverse section was the largest, the longitudinal section was the second, and the radial section was the smallest.It is also found that the transverse section is perpendicular to the bone unit, and the longitudinal and radial section is parallel to the bone unit. It can be inferred that the adhesion line between the bone unit and the bone stroma causes the cracks on the three sections to be folded to varying degrees.This makes the roughness of the three sections different and the fracture work in these three directions different.According to the statistical self-similarity of crack propagation paths during bone fracture, a fractal model of bone fracture along three directions is established. The energy dissipation of bone fracture along three different directions is calculated by using the energy dissipation formula of fractal theory.The obtained results are in good agreement with the bending test results.
【作者单位】：重庆大学煤矿灾害动力学与控制国家重点实验室非均质材料力学重庆市重点实验室;
【基金】：国家自然科学基金(11272367)
【分类号】：R68;R318.01

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